Detachable electrical connector



March 2, l948. w, s sc 2,436,914

DETAGHABLE ELECTRICAL CONNECTOR Filed Nov. 17, 1945 2 Sheets-Sheet 1 IN VEN TOR aim HIS ATTORNEY March 2, 194a. -E,W BREISH 2,436,914

DETACHABLE ELECTRICAL CONNECTOR Filed Nov. 17, 1945 2 Sheets-Sheet 2 IN VEN TOR Eqzya (0.31 961 012 BY a j 7 15 ATTORNEY Patented Mar. 2, 1948 UNITED STATES PATENT OFFICE I DETACHABLE ELECTRICAL CONNECTOR- Edgar W. Breisch, Edgewood, Pa., assignor to The Union Switch & Signal Company, Swiss- 7 vale, Pa., a corporation of Pennsylvania Application November 1'7, 1945, Serial No. 629,255

4 Claims. 1

My invention relates to detachable electrical connectors, and more particularly to a detachable connector permitting a relatively large number of electrical circuits to be simultaneously connected or disconnected.

Electrical units or assemblies having a large number of outside circuit connections must often be removed from service and a new unit put in its place and to disconnect the circuits one at a time from the terminals of the old unit and reconnect these circuits one at a time to terminals of the new unit may be a laborious operation. Such an operation creates a chance that a mistake may be made and may cause a serious delay in restoring the service of the system of which the unit is a part.

Accordingly, a feature of my invention is the provision of an improved detachable electrical connector.

Another feature of my invention is the provision of an improved detachable electrical connector that will successively maintain adequate electrical contact to carry small and extremely low voltage current or relatively large high voltage current.

Again, a feature ofmy invention is the provision of an improved connector of the type here involved wherewith a sufficient number of individual connectors of uniform construction are assembled to handle the circuits of a unit having a relatively large number of outside circuit connections with the different circuits carrying currents of different characteristics.

Still another feature of my invention is the provision of an improved electrical connector wherewith the associated unit can be moved along its supporting surface or shelf for locking the unit in place and firm contact maintained at the connector in all positions of such locking movement of the unit.

A more specific feature of my invention is the provision of a novel and improved contact spring for detachable electrical connectors of the type here involved. 7

Other features, objects and advantages of my invention will appear as the specification progresses.

To accomplish the foregoing features, objects and advantages of my invention I provide a con nector having two major parts, a socket body member carrying the female contact springs and a plug body member on which are mounted the male plug contacts, The socket body member has a base of insulation material proportioned to provide proper spacing for the required number of individual receptacles or sockets, the individual receptacles being preferably arranged in rows. The base is formed with rectangular compartments or recesses, one for each receptacle of the connector.

Each receptacle comprises a pair of contact springs secured to the hear; of a terminal post and inserted in a compartment for the terminal post to .extend through an opening in the rear of the base to receive nuts and washers for securing the contact springs in place in the compartment and for attaching a circuit wire thereto. The two springs of a receptacle are alike and are of a novel and improved composite form, such that essentially a line contact is maintained for the full length of the mating plug or contact pin of the connector when such plug contact is inserted between the springs. All contact springs of the connector are proportioned so that they can be used interchangeably for the various circuits passing through the connector and a relatively large number of different sizes of contact springs isavoided.

Theplug body member has a base of insulation material on which are mounted the different plug contacts or contact pins, the base being proportioned to provide a plug contact for each receptacle of the corresponding socket body member. These plug contacts are alike and are preferably cylindrical and are of a length and diameter predetermined to be inserted between the pair of contact springs of the corresponding receptacle. The rear of each plug contact extends through an opening in the rear of the base to receive nuts and washers for securing the plug contact to the base and for connection of a circuit wire.

It follows that with the two Wires of a circuit connected one to the terminal of a receptacle and one to the terminal of a plug contact. the circuit can be completed by inserting the plug contact into the spring of the receptacle and that by assigning a plug contact and a receptacle to each of a large number of different circuits, the different circuits can be simultaneously connected and disconnected by proper positioning of the socket body member and the plug body member.

In railway train communication equipment for which my connector finds particular use, the plug body member of a connector is fixed in place and the socket body member is securedito the frame of an associated portable unit or assembly, For example, the plug body member is fixed in position at the rear of a shelf on which the unit is to be housed and the socket body member is secured to the unit frame and the two are positioned relative to each other so as to complete the circuits when the unit is slid into place on the shelf. To avoid all danger of damaging the contact springs of the connector in handling the portable unit, the outer or forward end of the contact springs are preferably depressed a short distance below the outer surface of the insulation base of the socket b dy member.

In such railway train communication units or assemblies, an assembly clamping means is 11511:.

ally provided to firmly lock the assembly to the" shelf of the housing to avoid vibration, and a pre-' ferred form of such clamping means includes inthreaded portion. of the terminal post, and such terlo-cking gu de rails mounted on the frame' of the assembly and on the shelf, and the assembly is lockedthrough a longitudinal movement of the assembly with respect to the'shelf to Furthermore, since a relatively large force is re-' quired to insert a plug contact into the springs of the corresponding receptacle. means having a mechan cal advantage is provided with each assembly to aid in connecting and disconnecting the associated connector. I shall describe one form of detachable electrical connector embodying my invention, and shall then point out the novel features thereof in claims".

In the accompanying drawings, Fig. 1 is a vertical view showing a socket body member of a connector embodying my invention, the member being provided with two rows of four sockets or receptacles each. Fig, 2 is a sectional view taken along the line IIII of Fig. 1. Fig. 3 is a sectional view taken on the line III-III of Fig. Fig. 4 is a rear vertical view showing a plug body member which mates with the socket body member of Fig. 1. Fig. 5 is a sectional view taken on the line VV of Fig. l. Figs. 6a and 6b are enlarged views showing the shape of the contact springs of a connector embodying my invention.

In each of the several views like reference characters are used to designate similar parts. Referring to Fig, 1, a socket body member SB is provided with a base Ml of suitable insulation material. The base it is formed with a plurality of rectangular shaped compartments l l which are alike and, each of which compartments serves to house a receptacle or socket of the connector; These compartments are spaced to provide satisfactory clearance between the difierent sockets, and in Fig. 1 there are eight compartments arranged in two rows of four each. It'is clear, however, that the base is can be proportioned to provide a greater or a lesser number of compartments and to permit any desired arrangement of the compartment. The base i6 is provided with holes 52 for bolting the socket body member to a suitable supporting means, not shown, two bolt holes ii. being located at each end of the base It.

As best shown in Figs. 2 and 3, each compartment ll of the base houses a spring contact assembly including two contact springs [3 which are secured to the head of a terminal post [4 by rivets it). The springs I3 are alike and are" terminal postalso serves for the connection of circuit wires thereto. As shown in Fig. 1, two

sides of each compartment H are formed with an oifset or side member I! so that when the contact springs and the terminal post are slipped into the compartment the offsets I! serve to limit the travel of the contact springs I3 toward each other and provide definite openings into which the plug contacts can readily enter without danger of distortion. of the contact springs.

As best shown in Fig. 6a,; each contact spring l3 is formed with apredetermined shape. Each spring 13 is made of a suitable contacting material and has a straight contact" portion A and a cantilever portion B, the. portion B being formed by bending the spring at the forward end of the portion A toward the rear, that is, toward the terminal post 14. Eachspring I3 is slightly inclined or bent near its fixed point on the end of the terminal post to cause the contact portions A of the two springs of a receptacle or socket to be inclined toward: each: other so that the contact portions A are substantially parallel when a plug contact to be later described is inserted between the two springs. The reenf'orcing spring I 6 is placed back of the contact portion A of each spring I3 to aid in providing contact pressure between the spring i3 and'the plug contact at the tip or forward end of the spring. where the spring itself exerts the least pressure. With the. high pressure thus provided? at. the tip of the spring there. is a tendency of the contact portion A of the spring to bow at a point" about half way along the. contact portionof the spring. This distortion of the contact. portion A is couriteracted by forming the cantilever portion B of the spring with. three arches identified by the reference characters 0, D and E; The first one of the arches C is near the forward part of the spring, a second one of the archesD'is substantially at the mid point of the spring, and a third one of the arches E is near the rear of the spring. The first and third arches C and E extend in the right-hand direction as viewed inFig. 6a and the second arch D extends in the left-hand direction and thus as best shown in Fig. 3 the arches C and E of each spring !.3- of a socket engage the walls of the compartment and the arch'D engages the reenforcing spring at substantially the mid point of the contact portion when the spring assembly is slipped into the compartment.

I have found that as a result of this composite structure of the. contact springs, the contact springs of a receptacle maintain a line contact on both sides of the plug contact of the connector with substantially uniform pressure at all points along the line'ot contact and hence establishes the requisite low resistance high current capacity required for the wide range of difierent currents and voltages of the different circuits'for which theconnector may be used.

The length of; the contact portion A of the contact spring. is predetermined so asto provide the desired, contact area and theparts are so proportioned that the forward ends of the springs are slightly below the outer surface of the base ill and thereis no-danger of damage to the springsorof accidental short circuiting between the springsof the difierent sockets in the handling of the socket body memben after. circuit wires have been connected thereto.

' Referring to Fig; 4-, a plug body. member PB of the connector is formed with a, base I8 of suitable insulation material and this base .18 is provided with a series of compartments 1 9 for mount ing plugcontacts therein"; The base I8 is proportioned to mount'a' plug, one for each of the receptacles of the socket bodymember of-Fig. 1, and thus in Fig. 4 the basel8 is proportioned to mount two rows of four plugs each to matewith the two rowsof four receptacles each of the socket body member. Each plug contact is provided with a cylindrical contact portion 2| having a diameter and a length predetermined according to the spacing and length of the contact springs l3 of the receptacle. Each plug contact 20 is formed with a head 22 and with a terminal portion 23, the terminal portion 23 extending through an opening in the rear of the corresponding compartment and threaded to receive nuts and washers for securing the plug contact 'to the base and for the connection of circuit wires thereto. The base I8 is provided with bolt holes 24, two at each end of the base, for applying the plug body member to a suitable support, not shown.

As stated hereinbefore, connectors here disclosed find specific usefulness in railway train communication equipment, and it is lear that with the plug body member PB secured to a support of a shelf of a housing and the socket body member SB secured to the frame of an apparatus assembly, such assembly when positioned on the shelffor the socket body member to mate with the fixed plug body member can have its circuit connections completed through this connector.

Referring to Figs. 2, 5 and 612, it is to be noted that the width of the contact spring I3 is greater than the diameter of the contact portion 2| of the plugs 20. It is to be seen therefore that after the socket body member SB has been positioned for mating with the plug body member PB of the connector, the socket body member can be moved parallel with the longitudinal center line of the connector. This means that the assembly can be moved longitudinally along the shelffor locking the assembly in place on the shelf with the connector maintaining a firm contact at all positions in the movement along the shelf.

The electrical connector here disclosed has the advantages that assemblies having circuits that require a variety of voltages and current values can be successfully connected with the individual circuits connected through any individual receptacle of the connector, the contact springs and point contacts being formed to be used interchangeably with the various circuits. A line contact of substantially uniform pressure is maintained between the contact springs and the plug contact for the entire length of the plug contact. A horizontal and a vertical relative movement between the two major parts of the connector to meet all requirements for locking the associated assembly in place on the mounting is provided and at the same time a low resistance contact at all positions through the range of such looking movement is maintained for the connector. Damage and danger of short circulting the 6 springs during the handling of the associated unit are avoided and the connectors can be readily proportioned to provide the necessary receptacles to carry all the circuits of any particular assembly.

Although I haveherein shown and described but one form of detachable electrical connectors embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims without departing from the spirit and scope of my invention, j

Having thus described my invention, what I claim is:

- 1. In a detachable electrical connector using a cylindrical plug,--'the combination comprising, a receptacle including two flat contact springs and two flat reenforcing springs, said contact springs mounted in a rectangular compartment of an insulation baseto receive said plug and to engage diametrically opposite tangent lines of the plug, said reenforcing springs secured one to'each of said contact springs to reenforce the pressure be-' tween the contact spring and said plug at the forward end of the spring, each said contact spring formed with a portion bent toward the rear of the spring; and each such bent portion of a contact spring formed with three arches, a first one of which engages a wall of the compartment near the forward end of the compartment, a second one of which arches exerts pressure on the associated contact spring at a point near the mid point of the line of contact of the contact spring and the plug, and a third one of which arches engages the wall of the compartment near the rear of the compartment.

2. In a detachable electrical connector using a cylindrical plug contact of a preselected diameter and length, the combination comprising, an nsulation base having a rectangular compartment of a width at least equal to the diameter of the plug contact and a depth at least equal to the length of the plug contact, two fiat contact springs mounted in said compartment to make contact along diametrically oppositetangent lines of the plug contact when the plug contact is inserted into the compartment, each of said contact springs formed with a cantilever portion by bending the spring near the outer end toward the bottom of the compartment, and each of said cantilever portions formed with three arches two of which arches engage the wall of the compartment near the top and bottom respectively of the compartment and one of which arches exerts pressure on the spring back of the mid point of the line of contact of the spring and said plug contact.

3. In an electrical connector, the combination comprising, a pair of fiatcontact springs each having one end fixed to a terminal post and each bent to form a contact portion and a cantilever portion, the two contact portions being parallel to engage opposite contact surfaces of'a contact member when inserted between the contact springs; each said cantilever portion formed with three arches one near the forward end of the spring, one near the mid point of the spring and one near the fixed end of the spring; and the first and third mentioned arches extending away from the contact portion and the second mentioned arch extending toward the contact portion, whereby said contactsprings when mounted in a compartment of an insulation base engage walls of the compartment through said first and came second archto provide: substantially uniform contact pressureior thetulllength of the: contact portion.

4. In an electrical connector, the combination comprising, a pair of flat contact springs, each having one end fixed toa terminal post-and each shaped to form a contact portion and a cantilever portion, the two contact portions-being parallel to engage opposite contact-surfaces of a contact member when inserted between the contact springs; a reenforcing spring for each contact spring secured to said terminal post and disposed along: the. back of the contactspring to reenforce the contact pressure at the forward end of the contact portion; each said. cantilever portion formed with three arches onenear the forward end' 02 the. spring, one near themid point-0f the spring and. one. near the fixed. end-of the spring; and: the first and: third mentioned arches extending. away iromthe contact. portion. and. the secondmentioned arch extending toward the contact portion,v whereby sai'dtcontact springs when mounted in a compartmentrot' an. insulation base .1 engagev the walls on the: compartment. through said firstand. third; arches and; the I back of. the reenforcing. spring through: said second= arch. to provide a substantially uniform contact pressure '5: for the. fulllength or; the contact portion.

EDGAR W. BREISCH.

REFERENCIJ'S CHE!) The following referencesv are; ofi" record in the me of thisrpatent'? UNITED STATES" PATENTS Name- Date Harvey Apr. 21, 1936 Hansen et .al.t o Jan. 1-8; 1938 Number 2,162,453 Field-z ..r r June: 13;. 1939 2,258,269" Stoner eta Oct. 7,1941- 2 ,296,633 Falge .r.....i...... ..--.Sept. 22,v 1942 FOREIGN Pit'll-Eli'lfii Number. Country- Date 37 5,922 GreatBritainhw 1 932 703,904 Germ-any"......-..... i194i 

